Electrochemical corrosion behavior of corrosion-resistant steel for cargo oil tank were studied under different immersion corrosion time, and tests were carried in the PH=0.85, 10% NaCl solution, which temperature were 30°C. The electrochemical tested by the electrochemical polarization curve and electrochemical impedance spectroscopy (EIS), and the corrosion morphology and distribution of corrosion pit were observed under the metallography. The results indicate that along with the time extending, the corrosion potential of material moved from positive to negative, and then moved to positive. The corrosion current density also first reduced, then followed by the increasing and then decreasing, which indicated that the corrosion products of sample surface experienced a growth - dissolution - growth process, and presented a periodic corrosion rule. The position of corrosion pit mainly occurred around the pearlite.
Influence of shot peening on corrosion behavior of low alloy steel